Some communication networks, such as Internet Protocol (IP) networks or other broadband access networks, are configured to support Internet access and similar IP based services. In these networks, a user is granted access only upon successful authentication without regard to any emergency needs. Some of these networks, such as fixed networks, provide access and services to a subscriber or an authorized user by authenticating the user's device or the user's line instead of the user or the user's identity. Other networks, such as wireless networks, authenticate the user or his identity regardless of the device or line used, thus providing access to roaming or mobile users. However, new features or services are being added to these networks, such as emergency service support for unsubscribed or unauthorized users, roaming access for mobile or roaming users in fixed networks, or other features or services. Such features or services may require improving some of the networks' architectures.